Systems and methods having an optical magnetometer array with beam splitters

Abstract

An array of optically pumped magnetometers includes an array of vapor cells; and an array of beam splitters. The array of beam splitters is arranged into columns, including a first column, and rows. Each row and each column includes at least two of the beam splitters. The array of beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells.

What is claimed as new and desired to be protected by Letters Patent of the United States is: 
     
       1. An array of optically pumped magnetometers, comprising:
 an array of vapor cells; and 
 an array of beam splitters, wherein the array of beam splitters is arranged into a plurality of columns, including a first column, and a plurality of rows, wherein each row and each column comprises at least two of the beam splitters, wherein the array of beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the plurality of rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells, wherein the beam splitters are bonded together into a single block using optical adhesive. 
 
     
     
       2. The array of optically pumped magnetometers of  claim 1 , wherein the array of vapor cells is an N×M array and the array of beam splitters is an (N+1)×M array, wherein N and M are integers greater than one. 
     
     
       3. The array of optically pumped magnetometers of  claim 2 , wherein the array of beam splitters is configured to generate N×M beams of light. 
     
     
       4. The array of optically pumped magnetometers of  claim 3 , wherein the N×M beams of light have intensities that differ by no more than 5% from each other. 
     
     
       5. The array of optically pumped magnetometers of  claim 1 , wherein the first column has M of the beam splitters and an m-th one of the beam splitters in the first column has a reflectivity of 1/(M−m+1), wherein M is an integer greater than one and m is an integer ranging from 1 to M. 
     
     
       6. The array of optically pumped magnetometers of  claim 1 , wherein at least one row has a one of the beam splitters from the first column followed by N of the beam splitters after, wherein an n-th one of the N beam splitters has a reflectivity of 1/(N−n+1), wherein N is an integer greater than one and n is an integer ranging from 1 to N. 
     
     
       7. The array of optically pumped magnetometers of  claim 1 , further comprising a quarter waveplate disposed between the array of beam splitters and the array of vapor cells. 
     
     
       8. The array of optically pumped magnetometers of  claim 1 , further comprising a light source configured and arranged to direct light into the first column of the array of beam splitters. 
     
     
       9. The array of optically pumped magnetometers of  claim 1 , further comprising a reference detector configured to receive light that has passed through the beam splitters of the first column. 
     
     
       10. An array of optically pumped magnetometers, comprising:
 an array of vapor cells; and 
 an array of polarizing beam splitters, wherein the array of polarizing beam splitters is arranged into a plurality of columns, including a first column, and a plurality of rows, wherein each row and each column comprises at least two of the polarizing beam splitters, wherein the array of polarizing beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the plurality of rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells. 
 
     
     
       11. The array of optically pumped magnetometers of  claim 10 , further comprising waveplates disposed between adjacent ones of the polarizing beam splitters to rotate a polarization of a light beam exiting one of the polarizing beam splitters prior to entering another one of the polarizing beam splitters. 
     
     
       12. A magnetic field measurement system, comprising:
 an array of vapor cells; 
 an array of light detectors configured to receive light passing through the vapor cells; 
 an array of beam splitters, wherein the array of beam splitters is arranged into a plurality of columns, including a first column, and a plurality of rows, wherein each row and each column comprises at least two of the beam splitters, wherein the array of beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the plurality of rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells; and 
 a wearable article within which the array of vapor cells, array of light detectors and array of beam splitters are disposed. 
 
     
     
       13. The magnetic field measurement system of  claim 12 , further comprising at least one magnetic field generator disposed around at least one of the vapor cells to generate a magnetic field in the at least one of the vapor cells. 
     
     
       14. The magnetic field measurement system of  claim 12 , further comprising a light source configured and arranged to direct light into the first column of the array of beam splitters. 
     
     
       15. The magnetic field measurement system of  claim 14 , further comprising a computing device coupled to the array of light detectors and the light source. 
     
     
       16. The magnetic field measurement system of  claim 12 , further comprising a light source disposed in the wearable article and configured and arranged to direct light into the first column of the array of beam splitters. 
     
     
       17. The magnetic field measurement system of  claim 12 , wherein the first column has M of the beam splitters and an m-th one of the beam splitters in the first column has a reflectivity of 1/(M−m+1), wherein M is an integer greater than one and m is an integer ranging from 1 to M. 
     
     
       18. The magnetic field measurement system of  claim 12 , wherein at least one row has a one of the beam splitters from the first column followed by N of the beam splitters after, wherein an n-th one of the N beam splitters has a reflectivity of 1/(N−n+1), wherein N is an integer greater than one and n is an integer ranging from 1 to N. 
     
     
       19. The array of optically pumped magnetometers of  claim 10 , wherein the array of vapor cells is an N×M array and the array of polarizing beam splitters is an (N+1)×M array, wherein N and M are integers greater than one. 
     
     
       20. The array of optically pumped magnetometers of  claim 10 , further comprising a quarter waveplate disposed between the array of polarizing beam splitters and the array of vapor cells.